U.S. patent application number 11/990008 was filed with the patent office on 2010-01-28 for charge control device and electrically driven vehicle.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Tetsuhiro Ishikawa, Yukihiro Minezawa, Makoto Nakamura, Hichirosai Oyobe.
Application Number | 20100019734 11/990008 |
Document ID | / |
Family ID | 37809020 |
Filed Date | 2010-01-28 |
United States Patent
Application |
20100019734 |
Kind Code |
A1 |
Oyobe; Hichirosai ; et
al. |
January 28, 2010 |
Charge Control Device and Electrically Driven Vehicle
Abstract
Commercial AC voltage applied to an input terminal (90) from a
commercial power supply external to the vehicle is boosted by a
transformer (86) to a voltage level higher than the voltage (VB) of
an electricity storage device (B) to be applied to neutral points
(N1, N2). In a charging mode of the electricity storage device (B)
from a commercial power supply, all npn transistors of an inverter
(20, 30) are turned off. The AC voltage applied to the neutral
points (N1, N2) is rectified by an anti-parallel diode of the
inverter (20, 30) to be supplied onto a power supply line (PL2). A
boost converter (10) controls the charging current from the power
supply line (PL2) towards the electricity storage device (B).
Inventors: |
Oyobe; Hichirosai;
(Toyota-shi, JP) ; Ishikawa; Tetsuhiro;
(Nishikamo-gun, JP) ; Nakamura; Makoto;
(Okazaki-shi, JP) ; Minezawa; Yukihiro; (Anjo-shi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
TOYOTA-SHI
JP
|
Family ID: |
37809020 |
Appl. No.: |
11/990008 |
Filed: |
August 30, 2006 |
PCT Filed: |
August 30, 2006 |
PCT NO: |
PCT/JP2006/317602 |
371 Date: |
February 5, 2008 |
Current U.S.
Class: |
320/162 |
Current CPC
Class: |
B60K 6/365 20130101;
Y02T 10/62 20130101; H02J 7/143 20200101; Y02T 10/70 20130101; Y02T
10/7022 20130101; H02J 7/022 20130101; B60K 6/445 20130101; H02J
2207/20 20200101; Y02T 10/6239 20130101; Y02T 10/6269 20130101;
B60K 1/02 20130101; H02J 7/02 20130101 |
Class at
Publication: |
320/162 |
International
Class: |
H02J 7/04 20060101
H02J007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 1, 2005 |
JP |
2005-253841 |
Claims
1. A charge control device to charge an electricity storage device
(B), comprising: a first polyphase winding (12) that is
star-connected, a second polyphase winding (14) that is
star-connected, first and second inverters (20, 30) connected to
said first and second polyphase windings (12, 14), respectively,
and including an anti-parallel diode (D11-D16, D21-D26) connected
in parallel with each switching element (Q11-Q16, Q21-Q26), a
converter (10) arranged between each of said first and second
inverters (20, 30) and said electricity storage device (B), and a
boosting device (86) arranged between each of a first neutral point
(N1) of said first polyphase winding (12) and a second neutral
point (N2) of said second polyphase winding (14) and a power
supply, boosting voltage supplied from said power supply to a
voltage level higher than the voltage of said electricity storage
device (B) to provide the boosted voltage to said first and second
neutral points (N1, N2), wherein said first and second inverters
(20, 30) output the voltage boosted and applied to said first and
second neutral points (N1, N2) by said boosting device (86) to said
converter (10) via said anti-parallel diode (D11-D16, D21-D26),
said converter (10) receives voltage output from said first and
second inverters (20, 30) to charge said electricity storage device
(B).
2. The charge control device according to claim 1, wherein the
voltage supplied from said power supply is AC voltage, said
boosting device (86) includes a transformer boosting the AC voltage
supplied from said power supply, and said first and second
inverters (20, 30) use said anti-parallel diode (D11-D16, D21-D26)
to rectify the AC voltage boosted and applied to said first and
second neutral points (N1, N2) by said transformer for output to
said converter (10).
3. The charge control device according to claim 2, wherein said
power supply is an AC power supply for commercial use.
4. The charge control device according to claim 2, wherein said
first and second polyphase windings (12, 14) are included in first
and second electric motors (MG1, MG2) as stator windings,
respectively, and said first and second electric motors (MG1, MG2),
said electricity storage device (B), said converter (10), said
first and second inverters (20, 30), and a secondary winding (88)
of said transformer are incorporated in an electrically driven
vehicle with at least one of said first and second electric motors
(MG1, MG2) as a motive power source.
5. An electrically driven vehicle comprising: an electricity
storage device (B), a first electric motor (MG1) including a first
polyphase winding (12) that is star-connected as a stator winding,
a second electric motor (MG2) including a second polyphase winding
(14) that is star-connected as a stator winding, first and second
inverters (20, 30) provided corresponding to said first and second
electric motors (MG1, MG2), respectively, and including an
anti-parallel diode (D11-D16, D21-D26) connected in parallel with
each switching element (Q11-Q16, Q21-Q26), a converter (10)
arranged between each of said first and second inverters (20, 30)
and said electricity storage device (B), and a boosting device (86)
arranged between each of a first neutral point (N1) of said first
polyphase winding (12) and a second neutral point (N2) of said
second polyphase winding (14) and a power supply external to the
vehicle, boosting voltage supplied from said power supply to a
voltage level higher than the voltage of said electricity storage
device (B) to provide the boosted voltage to said first and second
neutral points (N1, N2), wherein when charging of said electricity
storage device (B) is effected from said power supply, said first
and second inverters (20, 30) output the voltage boosted and
applied to said first and second neutral points (N1, N2) by said
boosting device (86) to said converter (10) via said anti-parallel
diode (D11-D16, D21-D26), said converter (10) receives voltage
output from said first and second inverters (20, 30) to charge said
electricity storage device (B).
6. The electrically driven vehicle according to claim 5, wherein
the voltage supplied from said power supply is AC voltage, said
boosting device (86) includes a transformer boosting the AC voltage
supplied from said power supply, and said first and second
inverters (20, 30) use said anti-parallel diode (D11-D16, D21-D26)
to rectify the AC voltage boosted and applied to said first and
second neutral points (N1, N2) by said transformer for output to
said converter (10).
7. The electrically driven vehicle according to claim 6, wherein
said power supply is an AC power supply for commercial use.
8. The charge control device according to claim 1, wherein said
converter (10) charges said electricity storage device (B) while
controlling charging current of said electricity storage device (B)
based on a state of charge of said electricity storage device
(B).
9. The electrically driven vehicle according to claim 5, wherein
said converter (10) charges said electricity storage device (B)
while controlling charging current of said electricity storage
device (B) based on a state of charge of said electricity storage
device (B).
Description
TECHNICAL FIELD
[0001] The present invention relates to a charge control device and
an electrically driven vehicle. Particularly, the present invention
relates to a charge control device for an electricity storage
device incorporated in an electrically driven vehicle such as
electric vehicles and hybrid vehicles.
BACKGROUND ART
[0002] Japanese Patent Laying-Open No. 4-295202 discloses an
electric motor drive and power processing apparatus employed in an
electrically driven vehicle. This electric motor drive and power
processing apparatus includes a secondary battery, inverters IA and
IB, induction motors MA and MB, and a control unit. Induction
motors MA and MB include Y-connected windings CA and CB,
respectively. Input/output ports are connected to neutral points NA
and NB of windings CA and CB via an EMI filter.
[0003] Inverters IA and IB are provided corresponding to induction
motors MA and MB, respectively, and connected to windings CA and
CB, respectively. Inverters IA and IB are connected in parallel
with the secondary battery.
[0004] In this electric motor drive and power processing apparatus,
AC power is supplied across neutral points NA and NB of windings CA
and CB via an EMI filter from a single phase power supply connected
to the input/output port, when operating in a recharging mode, and
inverters IA and IB convert the AC power supplied across neutral
points NA and NB into DC power for charging the DC power
supply.
[0005] The electric motor drive and power processing apparatus
disclosed in Japanese Patent Laying-Open No. 4-295202 is
advantageous in that an additional AC/DC converter to charge the DC
power supply is not required, but disadvantageous in that switching
loss of inverters IA and IB occurs when the AC voltage supplied
from the single phase power supply connected to the input/output
port is converted into DC voltage according to the voltage level of
the DC power supply.
[0006] Further, switching control of inverters IA and IB may become
complicated since the AC voltage applied across neutral points NA
and NB of windings CA and CB is converted into DC voltage according
to the voltage level of the DC power supply by inverters IA and
IB.
DISCLOSURE OF THE INVENTION
[0007] In view of the foregoing, an object of the present invention
is to provide a charge control device without having to incorporate
an additional dedicated converter to charge an electricity storage
device from an external power supply, and eliminating the need of a
switching operation of the inverter.
[0008] Another object of the present invention is to provide an
electrically driven vehicle without having to incorporate an
additional dedicated converter to charge an electricity storage
device from a power supply external to the vehicle, and eliminating
the need of a switching operation of the inverter when charging
from the power supply external to the vehicle.
[0009] A charge control device according to the present invention
is directed to a charge control device to charge an electricity
storage device, and includes a first polyphase winding that is
star-connected, a second polyphase winding that is star-connected,
first and second inverters connected to the first and second
polyphase windings, respectively, and including an anti-parallel
diode connected in parallel with each switching element, a
converter arranged between each of the first and second inverters
and the electricity storage device, and a boosting device arranged
between each of a first neutral point of the first polyphase
winding and a second neutral point of the second polyphase winding
and a power supply, boosting voltage supplied from the power supply
to a voltage level higher than the voltage of the electricity
storage device to provide the boosted voltage to the first and
second neutral points. The first and second converters output the
voltage boosted and provided to the first and second neutral points
by the boosting device to the converter via the anti-parallel
diode. The converter charges the electricity storage device while
controlling the charging current of the electricity storage device
based on a state of charge of the electricity storage device.
[0010] In the charge control device of the present invention,
electric power from the power supply is supplied to the first
neutral point of the first polyphase winding and the second neutral
point of the second polyphase winding to effect charging of the
electricity storage device via the first and second inverters and
the converter. Since the boosting device boosts the voltage
supplied from the power supply to a voltage level higher than the
voltage of the electricity storage device and provides the boosted
voltage to the first and second neutral points, the first and
second inverters can supply the voltage applied at the first and
second neutral points to the converter via the anti-parallel diode
without having to operate each switching element. Current control
of the electricity storage device is effected through the
converter.
[0011] According to the charge control device of the present
invention, loss in charging can be reduced since switching of the
first and second inverters is not required. Further, control during
charging is facilitated since switching-control of the first and
second inverters is not required.
[0012] Preferably, the voltage supplied from the power supply is AC
voltage. The boosting device includes a transformer boosting the AC
voltage supplied from the power supply. The first and second
inverters use the anti-parallel diode to rectify the AC voltage
boosted and applied to the first and second neutral points by the
transformer for output to the converter.
[0013] Since the boosting device is constituted of a transformer in
the charge control device, the secondary side of the transformer is
insulated from the primary side. According to the charge control
device, the first and second inverters, the converter, and the
electricity storage device can be insulated from the power
supply.
[0014] Further preferably, the power supply is AC power supply for
commercial use.
[0015] According to the charge control device, the electricity
storage device can be charged readily and safely using the AC power
supply for commercial use such as at home.
[0016] Preferably, the first and second polyphase windings are
included in first and second electric motors, respectively, as
stator windings. The first and second electric motors, the
electricity storage device, the converter, the first and second
inverters, and the secondary winding of the transformer are
incorporated in an electrically driven vehicle with at least one of
first and second electric motors as the motive power source.
[0017] In the charge control device, the secondary winding of the
transformer is incorporated in the electrically driven vehicle
whereas the primary winding of the transformer is provided external
to the vehicle. According to the charge control device, the
electricity storage device of the electrically driven vehicle can
be charged in a non-contact manner from a power supply external to
the vehicle.
[0018] According to the present invention, an electrically driven
vehicle includes a electricity storage device, a first electric
motor having a first polyphase winding that is star-connected as a
stator winding, a second electric motor having a second polyphase
winding that is star-connected as a stator winding, first and
second inverters provided corresponding to the first and second
electric motors, respectively, and having an anti-parallel diode
connected in parallel with each switching element, a converter
arranged between each of the first and second inverters and the
electricity storage device, and a boosting device arranged between
each of a first neutral point of the first polyphase winding and a
second neutral point of the second polyphase winding and a power
supply external to the vehicle, boosting voltage supplied from the
power supply to a voltage level higher than the voltage of the
electricity storage device to provide the boosted voltage to the
first and second neutral points. When charging of the electricity
storage device is effected from the power supply, the first and
second inverters output the voltage boosted and applied to the
first and second neutral points by the boosting device to the
converter via the anti-parallel diode, and the converter charges
the electricity storage device while controlling the charging
current of the electricity storage device based on the state of
charge of the electricity storage device.
[0019] According to the electrically driven vehicle of the present
invention, electric power is supplied from a power supply external
to the vehicle to the first neutral point of the first electric
motor and the second neutral point of the second electric motor,
and charging of the electricity storage device is effected via the
first and second inverters and converter. Since the boosting device
boosts the voltage supplied from the power supply to a voltage
level higher than the voltage of the electricity storage device for
provision to the first and second neutral points, the first and
second inverters can supply the voltage applied to the first and
second neutral points to the converter via the anti-parallel diode
without having to operate each switching element. Current control
of the electricity storage device is effected through the
converter.
[0020] According to the electrically driven vehicle of the present
invention, the electricity storage device can be charged from a
power supply external to the vehicle without a dedicated converter
for charging. Since switching of the first and second inverters is
not required during charging, the loss in charging can be reduced.
Further, control during charging is facilitated since
switching-control of the first and second inverters is not
required.
[0021] Preferably, the voltage supplied from the power supply is AC
voltage. The boosting device includes a transformer boosting the AC
voltage supplied from the power supply. The first and second
inverters use the anti-parallel diode to rectify the AC voltage
boosted and applied to the first and second neutral points by the
transformer for output to the converter.
[0022] Since the boosting device is constituted of a transformer in
the electrically driven vehicle, the secondary side of the
transformer is insulated from the primary side. According to the
electrically driven vehicle, the first and second inverters, the
converter, and the electricity storage device can be insulated from
the power supply.
[0023] Further preferably, the power supply is AC power supply for
commercial use.
[0024] According to the electrically driven vehicle, the
electricity storage device can be charged readily and safely using
the commercial AC power supply such as at home.
[0025] Since the voltage from a power supply is boosted to a
voltage level higher than the voltage of the electricity storage
device by the boosting device in the present invention to be
supplied to the first and second neutral points, switching
operation of the first and second inverters can be eliminated.
Therefore, the loss in charging can be reduced. Further, control
during charging is facilitated.
[0026] By employing a transformer for the boosting device, the
first and second inverters, the converter, and the electricity
storage device can be insulated from the power supply. Further, the
electricity storage device can be charged from an external power
supply in a non-contact manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is an entire block diagram of a hybrid vehicle
presented as an example of an electrically driven vehicle according
to an embodiment of the present invention.
[0028] FIG. 2 is a functional block diagram of a control device
shown in FIG. 1.
[0029] FIG. 3 is a flow chart of a control configuration of a
program related to determination of charging execution of the
electricity storage device by an AC input control unit shown in
FIG. 2.
[0030] FIG. 4 is a functional block diagram of a converter control
unit shown in FIG. 2.
[0031] FIG. 5 is a functional block diagram of first and second
inverter control units shown in FIG. 2.
[0032] FIG. 6 is an entire block diagram of a hybrid vehicle
according to a modification of an embodiment of the present
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0033] An embodiment of the present invention will be described
hereinafter in detail with reference to the drawings. In the
drawings, the same or corresponding elements have the same
reference characters allotted, and description thereof will not be
repeated.
[0034] FIG. 1 is an entire block diagram of a hybrid vehicle
presented as an example of an electrically driven vehicle according
to an embodiment of the present invention. Referring to FIG. 1, a
hybrid vehicle 100 includes an electricity storage device B, a
boost converter 10, inverters 20 and 30, motor generators MG1 and
MG2, an engine 4, a power split mechanism 3, a wheel 2, and a
control device 60.
[0035] Hybrid vehicle 100 also includes an input terminal 90, a
rectifier 92, an inverter 94, a transformer 86, and AC lines ACL1
and ACL2. Furthermore, hybrid vehicle 100 includes power supply
lines PL1 and PL2, a ground line SL, capacitors C1 and C2, U-phase
lines UL1-UL3, V-phase lines VL1-VL3, W-phase lines WL1-WL3,
voltage sensors 71, 72 and 74, and current sensors 80, 82 and
84.
[0036] Power split mechanism 3 is linked to engine 4 and motor
generators MG1 and MG2 to split the power therebetween. For
example, a planetary gear mechanism including three rotational
shafts of a sun gear, planetary carrier, and ring gear can be
employed as power split mechanism 3. The three rotational shafts
are connected to each rotational shaft of engine 4 and motor
generators MG1 and MG2. For example, by passing the crankshaft of
engine 4 through the center of the hollow rotor of motor generator
MG1, engine 4 and motor generators MG1 and MG2 can be connected
mechanically to power split mechanism 3.
[0037] The rotational shaft of motor generator MG2 is linked to
wheel 2 by a reduction gear and/or actuating operation gear not
shown. Further, a reduction gear for the rotational shaft of motor
generator MG2 can be incorporated in power split mechanism 3.
[0038] Motor generator MG1 is incorporated in hybrid vehicle 100,
operating as a power generator driven by engine 4, and as electric
motor capable of startup of engine 4. Motor generator MG2 is
incorporated in hybrid vehicle 100 as an electric motor that drives
driving wheel 2 qualified as a driven wheel.
[0039] Electricity storage device B has a positive electrode
connected to power supply line PL1 and a negative electrode
connected to ground line SL. Capacitor C1 is connected between
power supply line PL1 and ground line SL.
[0040] Boost converter 10 includes a reactor L, npn transistors Q1
and Q2, and anti-parallel diodes D1 and D2. NPN transistors Q1 and
Q2 are connected in series between power supply line PL2 and ground
line SL. Between the collector and emitter of npn transistors Q1
and Q2 is connected anti-parallel diodes D1 and D2, respectively,
so as to conduct a current flow from the emitter side to the
collector side. Reactor L has one end connected to the connection
node of npn transistors Q1 and Q2 and the other end connected to
power supply line PL1.
[0041] For the npn transistor set forth above and described
hereinafter in the present description, an IGBT (Insulated Gate
Bipolar Transistor), for example, can be employed. Further, a power
switching element such as a power MOSFET (Metal Oxide Semiconductor
Field-Effect Transistor) can be employed instead of an npn
transistor.
[0042] Capacitor C2 is connected between power supply line PL2 and
ground line SL. Inverter 20 includes a U-phase arm 22, a V-phase
arm 24 and a W-phase arm 26. U-phase arm 22, V-phase arm 24 and
W-phase arm 26 are connected in parallel between power supply line
PL2 and ground line SL. U-phase arm 22 is formed of npn transistors
Q11 and Q12 connected in series. V-phase arm 24 is formed of npn
transistors Q13 and Q14 connected in series. W-phase arm 26 is
formed of npn transistors Q15 and Q16 connected in series. Between
the collector and emitter of npn transistors Q11-Q16 are connected
anti-parallel diodes D11-D16, respectively, conducting a current
flow from the emitter side to the collector side.
[0043] Motor generator MG1 includes a 3-phase coil 12 as the stator
coil. U-phase coil U1, V-phase coil V1 and W-phase coil W1
constituting 3-phase coil 12 have one ends connected to each other
to form a neutral point N1, and the other ends connected to the
connection nodes of respective npn transistors of U-phase arm 22,
V-phase arm 24 and W-phase arm 26 of inverter 20.
[0044] Inverter 30 includes a U-phase arm 32, a V-phase arm 34 and
a W-phase arm 36. Motor generator MG2 includes a 3-phase coil 14 as
the stator coil. The configurations of inverter 30 and motor
generator MG2 are similar to those of inverter 20 and motor
generator MG1, respectively.
[0045] Transformer 86 includes a primary coil 87 and a secondary
coil 88. Secondary coil 88 is connected to neutral points N1 and N2
of 3-phase coils 12 and 14 of motor generators MG and MG2 via AC
lines ACL1 and ACL2, respectively. Primary coil 87 is connected to
inverter 94. Rectifier 92 is connected at the primary side of
inverter 94. Input terminal 90 is connected at the primary side of
rectifier 92.
[0046] Electricity storage device B is a rechargeable DC power
supply such as a nickel-hydrogen or lithium-ion secondary battery.
Electricity storage device B provides DC power to boost converter
10. Electricity storage device B is charged by boost converter 10.
A capacitor of large capacitance can be employed for electricity
storage device B.
[0047] Voltage sensor 71 detects voltage VB of electricity storage
device B to provide the detected voltage VB to control device 60.
Current sensor 84 detects current IB input/output with respect to
electricity storage device B to provide the detected current IB to
control device 60. Capacitor C1 smoothes the voltage variation
between power supply line PL1 and ground line SL.
[0048] Boost converter 10 responds to a signal PWC from control
device 60 to boost the DC voltage from electricity storage device B
using reactor L and provides the boosted voltage onto power supply
line PL2. Specifically, based on signal PWC from control device 60,
boost converter 10 accumulates the flowing current in response to
the switching operation of npn transistor Q2 as magnetic field
energy at reactor L to boost the DC voltage from electricity
storage device B. Boost converter 10 outputs the boosted voltage
onto power supply line PL2 via anti-parallel diode D1 in
synchronization with the OFF-timing of npn transistor Q2. When
charging of electricity storage device B is effected from a
commercial power supply external to the vehicle and connected to
input terminal 90, boost converter 10 controls the charging current
of electricity storage device B based on signal PWC from control
device 60.
[0049] Capacitor C2 smoothes the voltage variation between power
supply line PL2 and ground line SL. Voltage sensor 72 detects the
voltage across the terminals of capacitor C2, i.e. voltage VH on
power supply line PL2 with respect to ground line SL, and provides
the detected voltage VH to control device 60.
[0050] Based on a signal PWM1 from control device 60, inverter 20
converts the DC voltage from power supply line PL2 into 3-phase AC
voltage, which is provided to motor generator MG1. Accordingly,
motor generator MG1 is driven to generate the specified torque.
Inverter 20 converts the 3-phase AC voltage generated by motor
generator MG1 upon receiving the output of engine 4 into DC voltage
based on signal PWM1 from control device 60, and outputs the
converted DC voltage onto power supply line PL2.
[0051] Based on a signal PWM2 from control device 60, inverter 30
converts the DC voltage from power supply line PL2 into 3-phase AC
voltage, and outputs the converted 3-phase AC voltage to motor
generator MG2. Accordingly, motor generator MG2 is driven to
generate the specified torque. In a regenerative braking mode of
the vehicle, inverter 30 converts the 3-phase AC voltage generated
by motor generator MG2 upon receiving the rotational force from
wheel 2 into DC voltage based on signal PWM2 from control device
60, and provides the converted DC voltage onto power supply line
PL2.
[0052] As used herein, "regenerative braking" includes the braking
operation with the regenerative power generation when the driver of
the hybrid vehicle depresses the foot brake, or reducing the speed
(or ceasing acceleration) of the vehicle during regenerative power
generation by turning off the accelerator pedal during driving
without operating the foot brake.
[0053] When charging of electricity storage device B is effected
from a commercial power supply connected to input terminal 90,
inverters 20 and 30 rectify AC voltage boosted and applied to
neutral points N1 and N2 of 3-phase coils 12 and 14 by transformer
86 for output onto power supply line PL2. When electricity storage
device B is to be charged from a commercial power supply, npn
transistors Q11-Q16 and Q21-Q26 of inverters 20 and 30 are all
turned off (gate shut down), and rectification is conducted by
anti-parallel diodes D11-D16 and D21-D26.
[0054] Motor generators MG1 and MG2 are 3-phase AC electric motors,
and constituted of, for example, 3-phase alternating synchronous
electric motors. Motor generator MG1 employs the output of engine 4
to generate 3-phase AC voltage, which is output to inverter 20.
Motor generator MG1 generates driving power by the 3-phase AC
voltage from inverter 20 to start engine 4. Motor generator MG2
generates the drive torque of the vehicle by the 3-phase AC voltage
received from inverter 30. In a regenerative braking mode of the
vehicle, motor generator MG2 generates and outputs to inverter 30 a
3-phase AC voltage.
[0055] Transformer 86 boosts the high-frequency AC voltage from
inverter 94 to a voltage level higher than voltage VB of
electricity storage device B, and outputs the boosted AC voltage
onto AC lines ACL1 and ACL2. Transformer 86 insulates respective
elements such as inverters 20 and 30 incorporated in the vehicle
from the commercial power supply connected to input terminal 90.
Voltage sensor 74 detects voltage VAC between AC lines ACL1 and
ACL2 and outputs the detected voltage VAC to control device 60.
[0056] Input terminal 90 serves to receive commercial AC voltage
when electricity storage device B is to be charged from a
commercial power supply external to the vehicle. Rectifier 92
rectifies the commercial AC voltage supplied to input terminal 90
for output to inverter 94. Inverter 94 converts the DC voltage from
rectifier 92 into AC voltage of high frequency, which is output to
primary coil 87 of transformer 86.
[0057] The reason why the commercial AC voltage from the commercial
power supply is increased in frequency by means of rectifier 92 and
inverter 94 is that the size of transformer 86 can be reduced by
operating transformer 86 at high frequency.
[0058] Current sensor 80 detects motor current MCRT1 flowing to
motor generator MG1 and outputs detected motor current MCRT1 to
control device 60. Current sensor 82 detects motor current MCRT2
flowing to motor generator MG2 and outputs detected motor current
MCRT2 to control device 60.
[0059] Control device 60 generates signal PWC to drive boost
converter 10 and signals PWM1 and PWM2 to drive inverters 20 and
30, respectively. The generated signals PWC, PWM1 and PWM2 are
output to boost converter 10, inverter 20, and inverter 30,
respectively.
[0060] Control device 60 determines whether to charge electricity
storage device B from the commercial power supply connected to
input terminal 90, and when charging of electricity storage device
B is to be executed, turns off all npn transistors Q11-Q16 and
Q21-Q26 of inverters 20 and 30, and effects charging control of
electricity storage device B by means of boost converter 10.
[0061] FIG. 2 is a functional block diagram of control device 60 of
FIG. 1. Referring to FIG. 2, control device 60 includes a converter
control unit 61, a first inverter control unit 62, a second
inverter control unit 63, and an AC input control unit 64.
[0062] Based on voltage VB from voltage sensor 71, voltage VH from
voltage sensor 72, torque command values TR1 and TR2 as well as
motor speed MRN1 and MRN2 of motor generators MG1 and MG2 output
from HV-ECU (not shown; the same applies hereinafter), current IB
from current sensor 84, and also a charging current target value
IBR and charge control command CHG from AC input control unit 64,
converter control unit 61 generates a signal PWC to turn on/off npn
transistors Q1 and Q2 of boost converter 10 to provide the
generated signal PWC to boost converter 10.
[0063] Based on torque command value TR1 and motor current MCRT1 of
motor generator MG1 and voltage VH, first inverter control unit 62
generates a signal PWM1 to turn on/off npn transistors Q11-Q16 of
inverter 20 to provide the generated signal PWM1 to inverter 20.
Upon receiving a gate off command GOFF from AC input control unit
64, first inverter control unit 62 generates and provides to
inverter 20 signal PWM1 to turn off all npn transistors Q11-Q16 of
inverter 20.
[0064] Based on torque command value TR2 and motor current MCRT2 of
motor generator MG2 and voltage VH, second inverter control unit 63
generates signal PWM2 to turn on/off npn transistors Q21-Q26 of
inverter 30. The generated signal PWM2 is output to inverter 30.
Upon receiving gate off command GOFF from AC input control unit 64,
second inverter control unit 63 generates and provides to inverter
30 signal PWM2 to turn off all npn transistors Q21-Q26 of inverter
30.
[0065] Based on a signal IG from an ignition key (or ignition
switch; the same applies hereinafter) not shown and voltage VAC
from voltage sensor 74, AC input control unit 64 determines whether
to effect charging of electricity storage device B from the
commercial power supply external to the vehicle. During execution
of charging of electricity storage device B, AC input control unit
64 outputs gate off command GOFF to first and second inverter
control units 62 and 63, and outputs charge control command CHG to
converter control unit 61. Charge control command CHG is a command
to instruct converter control unit 61 to effect charge control of
electricity storage device B.
[0066] When charging of electricity storage device B is executed,
AC input control unit 64 calculates a charging current target value
IBR of electricity storage device B based on the state of charge
(SOC) of electricity storage device B received from HV-ECU, and
provides the calculated charging current target value IBR to
converter control unit 61. The SOC of electricity storage device B
is calculated based on the well-known scheme by a battery ECU not
shown.
[0067] FIG. 3 is a flowchart of a control configuration of a
program related to determination of charge execution of electricity
storage device B by AC input control unit 64 shown in FIG. 2. The
process of this flowchart is invoked and executed from the main
routine at a constant time interval or every time a predetermined
condition is established.
[0068] Referring to FIG. 3, AC input control unit 64 determines
whether the ignition key has been turned to the OFF position based
on signal IG from the ignition key (step S10). Upon determination
that the ignition key is not at the OFF position (NO at step S10),
AC input control unit 64 determines that it is inappropriate to
connect the commercial power supply to input terminal 90 for
charging of electricity storage device B, and control proceeds to
step S60. Control is transferred to the main routine.
[0069] When determination is made that the ignition key corresponds
to the OFF position at step S10 (YES at step S10), AC input control
unit 64 determines whether commercial AC voltage from the
commercial power supply is applied to input terminal 90 based on
voltage VAC from voltage sensor 74 (step S20). Upon determination
that the commercial AC voltage is not input (NO at step S20), AC
input control unit 64 does not effect the charging process, and
control proceeds to step S60. Thus, control returns to the main
routine.
[0070] When input of commercial AC voltage to input terminal 90 is
confirmed (YES at step S20), AC input control unit 64 calculates
charging current target value IBR of electricity storage device B
based on the SOC of electricity storage device B. The calculated
charging current target value IBR is output to converter control
unit 61 (step S30). For example, when the SOC of electricity
storage device B is lower than the reference value corresponding to
a sufficient SOC of electricity storage device B, AC input control
unit 64 sets charging current target value IBR of electricity
storage device B at a predetermined value. The value of charging
current target value IBR may be varied according to the SOC of
electricity storage device B.
[0071] When the charging current of electricity storage device B is
set at step S30, AC input control unit 64 outputs gate off command
GOFF to first and second inverter control units 62 and 63 (step
S40). In response, first and second inverter control units 62 and
63 turn off all npn transistors Q11-Q16 and Q21-Q26 in inverters 20
and 30, respectively. Switching of inverters 20 and 30 is
suppressed during charging of electricity storage device B from the
commercial power supply connected to input terminal 90.
[0072] Following the process of step S40, AC input control unit 64
outputs charge control command CHG to converter control unit 61 to
instruct converter control unit 61 to execute charge control of
electricity storage device B (step S50). Accordingly, converter
control unit 61 executes charging control of electricity storage
device B, as will be described afterwards. During charging of
electricity storage device B, boost converter 10 charges
electricity storage device B while controlling the charging current
of electricity storage device B at the level of charging current
target value IBR. Then, control returns to the main routine (step
S60).
[0073] FIG. 4 is a functional block diagram of converter control
unit 61 of FIG. 2. Referring to FIG. 4, converter control unit 61
includes an inverter input voltage command calculation unit 111,
subtracters 112 and 114, a PI control unit 113, a feedback voltage
command calculation unit 115, a duty ratio calculation unit 116,
and a PWM signal conversion unit 117.
[0074] Inverter input voltage command calculation unit 111
calculates the optimum value (target value) of the inverter input
voltage, i.e. voltage command VH_com, based on torque command
values TR1 and TR2 and motor speed MRN1 and MRN2 from HV-ECU. The
calculated voltage command VH_com is output to feedback voltage
command calculation unit 115.
[0075] Subtracter 112 receives charging current target value IBR
from AC input control unit 64 and current IB from current sensor 84
to subtract current IB from charging current target value IBR. The
calculated result is output to PI control unit 113.
[0076] PI control unit 113 carries out a proportional and integral
operation with the deviation between charging current target value
IBR and current IB received from subtracter 112 as the input. The
calculated result is output to subtracter 114.
[0077] Subtracter 114 receives the output value of PI control unit
113 and voltage VH from voltage sensor 72 to subtract the output
value of PI control unit 113 from voltage VH. The calculated result
is output to feedback voltage command calculation unit 115 as
voltage command VH_IB.
[0078] Feedback voltage command calculation unit 115 receives
voltage VH, charge control command CHG from AC input control unit
64, voltage command VH_com from inverter input voltage command
calculation unit 111, and voltage command VH_IB from subtracter
114. When charge control command CHG is inactive, feedback voltage
command calculation unit 115 calculates feedback voltage command
VH_fb to control voltage VH at the level of voltage command VH_com,
based on voltage VH and voltage command VH_com from inverter input
voltage command calculation unit 111. The calculated feedback
voltage command VH_fb is output to duty ratio calculation unit
116.
[0079] When charge control command CHG is active, feedback voltage
command calculation unit 115 calculates feedback voltage command
VH_fb to control voltage VH at the level of voltage command VH_IB,
based on voltage VH and voltage command VH_IB from subtracter 114.
The calculated feedback voltage command VH_fb is output to duty
ratio calculation unit 116.
[0080] Based on voltage VB from voltage sensor 71, voltage VH, and
feedback voltage command VH_fb from feedback voltage command
calculation unit 115, duty ratio calculation unit 116 calculates
the duty ratio to control voltage VH at the level of voltage
command VH_com or VH_IB. The calculated duty ratio is output to PWM
signal conversion unit 117.
[0081] Based on duty ratio from duty ratio calculation unit 116,
PWM signal conversion unit 117 generates a PWM (Pulse Width
Modulation) signal to turn on/off npn transistors Q1 and Q2 of
boost converter 10. The generated PWM signal is output to npn
transistors Q1 and Q2 of boost converter 10 as signal PWC.
[0082] When charge control command CHG from AC input control unit
64 is inactive, i.e. when charging of electricity storage device B
from the commercial power supply is not executed, converter control
unit 61 controls the switching duty of the upper arm and lower arm
of boost converter 10 such that voltage VH is controlled at the
level of voltage command VH_com calculated by inverter input
voltage command calculation unit 111.
[0083] In contrast, when charge control command CHG from AC input
control unit 64 is active, i.e. charging of electricity storage
device B from the commercial power supply is executed, the
switching duty of the upper arm and lower arm of boost converter 10
is controlled such that charging current IB of electricity storage
device B is controlled at the level of charging current target
value IBR.
[0084] FIG. 5 is a functional block diagram of first and second
inverter control units 62 and 63 of FIG. 2. Referring to FIG. 5,
each of first and second inverter control units 62 and 63 includes
a phase voltage calculation unit 120 for motor control and a PWM
signal conversion unit 122.
[0085] Motor control phase voltage calculation unit 120 receives
from voltage sensor 72 a voltage VH that is the input voltage of
inverters 20 and 30, receives motor current MCRT1 (or MCRT2)
flowing through each phase of motor generator MG1 (or MG2) from
current sensor 80 (or 82), and receives torque command value TR1
(or TR2) from HV-ECU. Motor control phase voltage calculation unit
120 calculates the voltage to be applied to each phase coil of
motor generator MG1 (or MG2) based on the input values. The
calculated voltage of each phase coil is output to PWM signal
conversion unit 122.
[0086] When gate off command GOFF from AC input control unit 64 is
inactive, PWM signal conversion unit 122 responds to the voltage
command of each phase coil received from motor control phase
voltage calculation unit 120 to generate a signal PWM1_0 (one type
of signal PWM1) (or signal PWM2_0 (one type of signal PWM2)) that
turns on/off each of npn transistors Q11-Q16 (or Q21-Q26) of
inverter 20 (or 30). The generated signal PWM1_0 (or PWM2_0) is
output to each of npn transistors Q11-Q16 (or Q21-Q26) of inverter
20 (or 30).
[0087] Thus, each of npn transistors Q11-Q16 (or Q21-Q26) is
switching-controlled, and the current to be conducted to each phase
of motor generator MG1 (or MG2) is regulated such that motor
generator MG1 (or MG2) outputs the specified torque. As a result,
motor torque corresponding to torque command value TR1 (or TR2) is
output.
[0088] When gate off command GOFF from AC input control unit 64 is
active, PWM signal conversion unit 122 generates a signal PWM1_1
(one type of signal PWM1) (or signal PWM2_1 (one type of signal
PWM2)) that turns off all of npn transistors Q11-Q16 (or Q21-Q26)
of inverter 20 (or 30), irrespective of the output of motor control
phase voltage calculation unit 120. The generated signal PWM1_1 (or
PWM2_1) is output to npn transistors Q11-Q16 (or Q21-Q26) of
inverter 20 (or 30).
[0089] Referring to FIG. 1 again, the entire operation of hybrid
vehicle 100 will be described. This hybrid vehicle 100 runs with
engine 4 and motor generator MG2 as the motive power source.
Electric power is generated by motor generator MG1 using the output
of engine 4 to supply the electric power to electricity storage
device B. In a regenerative braking mode of the vehicle,
regenerative power generation is conducted by motor generator MG2
using the rotation force of motor generator MG2 to supply electric
power to electricity storage device B.
[0090] At hybrid vehicle 100, electricity storage device B can be
charged using the commercial power supply connected to input
terminal 90. The commercial AC voltage applied to input terminal 90
is converted into AC voltage of high frequency by rectifier 92 and
inverter 94 to be applied to transformer 86.
[0091] Transformer 86 boosts the high-frequency AC voltage from
inverter 94 to a voltage level higher than the level of voltage VB
of electricity storage device B. The boosted AC voltage is output
to neutral points N1 and N2 of 3-phase coils 12 and 14 of motor
generators MG1 and MG2 via AC lines ACL1 and ACL2. The AC voltage
applied to neutral points N1 and N2 is rectified by inverters 20
and 30 to be output onto power supply line PL2.
[0092] When charging of electricity storage device B is effected
from the commercial power supply, each of npn transistors Q11-Q16
and Q21-Q26 of inverters 20 and 30 are all turned off without
switching. Since AC voltage applied to neutral points N1 and N2 is
boosted to a voltage level higher than the voltage VB of
electricity storage device B by transformer 86, anti-parallel
diodes D16-D16 and D26-D26 of inverters 20 and 30 function as
rectifying circuits to rectify the AC voltage applied to neutral
points N1 and N2 for output onto power supply line PL2.
[0093] Control device 60 sets the charging current of electricity
storage device B based on the SOC of electricity storage device B.
Boost converter 10 responds to signal PWC from control device 60 to
charge electricity storage device B while controlling the charging
current from power supply line PL2 towards electricity storage
device B.
[0094] According to the present embodiment, the supply of AC power
from the commercial power supply external to the vehicle to neutral
points N1 and N2 of 3-phase coils 12 and 14 of motor generators MG1
and MG2 allows charging of electricity storage device B without
having to provide a dedicated AC/DC converter additionally.
[0095] Since transformer 86 is provided between input terminal 90
and neutral points N1 and N2 such that the commercial AC voltage
from the commercial power supply is boosted to a voltage level
higher than voltage VB of electricity storage device B to be
applied to neutral points N1 and N2, switching of inverters 20 and
30 is not required when electricity storage device B is charged
from a commercial power supply. Therefore, switching loss at
inverters 20 and 30 can be eliminated, allowing reduction of the
loss in charging. Further, insulation of devices such as motor
generators MG1 and MG2 and inverters 20 and 30 from the commercial
power supply can be ensured.
[0096] The path from input terminal 90 to primary coil 87 of
transformer 86 may be provided external to the hybrid vehicle.
[0097] FIG. 6 is an entire block diagram of a hybrid vehicle
according to a modification of the embodiment of the present
invention. Referring to FIG. 6, a hybrid vehicle 100A includes
secondary coil 88 of transformer 86. Primary coil 87 of transformer
86, input terminal 90, rectifier 92, and inverter 94 are provided
external to hybrid vehicle 100A.
[0098] Primary coil 87 of transformer 86, input terminal 90,
rectifier 92 and inverter 94 are constituted as the charging
equipment external to the vehicle. When electricity storage device
B is to be charged from the commercial power supply connected to
input terminal 90, primary coil 87 is set in the proximity of
secondary coil 88 incorporated in hybrid vehicle 100A to allow
boosting of commercial AC voltage from the commercial power supply
for application to neutral points N1 and N2.
[0099] According to hybrid vehicle 100A, charging is allowed with
respect to hybrid vehicle 100A in a non-contact manner when
electricity storage device B is charged from a commercial power
supply. Further, since primary coil 87 of transformer 86, input
terminal 90, rectifier 92 and inverter 94 are provided external to
the vehicle, the weight of hybrid vehicle 100A can be reduced as
compared to hybrid vehicle 100 set forth above.
[0100] Although the embodiment set forth above includes rectifier
92 and inverter 94 between input terminal 90 and transformer 86 in
order to reduce the size of transformer 86, the present invention
is applicable even if rectifier 92 and inverter 94 are absent.
[0101] Although a hybrid vehicle has been described as an example
of an electrically driven vehicle of the present invention in the
embodiment set forth above, the present invention is also
applicable to an electric vehicle as well as a fuel cell vehicle
incorporating an electricity storage device such as a battery or
capacitor in addition to a fuel cell.
[0102] In the description set forth above, 3-phase coils 12 and 14
correspond to "first polyphase winding" and "second polyphase
winding", respectively, of the present invention. Inverters 20 and
30 correspond to "first inverter" and "second inverter",
respectively, of the present invention. Boost converter 10 and
transformer 86 correspond to "converter" and "boosting device",
respectively, of the present invention. Further, motor generators
MG1 and MG2 correspond to "first electric motor" and "second
electric motor", respectively, of the present invention.
[0103] It should be understood that the embodiments disclosed
herein are illustrative and non-restrictive in every respect. The
scope of the present invention is defined by the terms of the
claims, rather than the description above, and is intended to
include any modification within the scope and meaning equivalent to
the terms of the claims.
* * * * *